Process of obtaining a double-oriented film, co-extruded, and of low thickness made by a three bubble process that at the time of being thermoformed provides a uniform thickness in the produced tray

Abstract

The present invention relates to provides a double-oriented film, co-extrude, and of low thickness, with a layered composition that gives the property of being of high barrier to gases and manufactured by the process of co-extrusion of 3 bubbles, which gives the property of when being thermoformed, ensure the distribution of uniform thickness in the walls, base, folds, and corners of the formed tray saving a minimum of 50% of plastic without diminishing its gas barrier and its resistance to puncture.

Having described enough my invention, I consider it as a novelty and therefore claim as my exclusive property, contained in the following clauses: 
     
       1. A low thickness film comprising:
 a multi-layer tubular strip having:
 20 to 40% by weight of at least one polyamide, 
 
 from 0.01 to 10% by weight of ethyl vinyl alcohol, 
 from 10% to 15% by weight of a sealing agent, and 
 at least 20% by weight of at least one poly olefin; 
 wherein the low thickness film has a uniform thickness of between 0.4 to 0.7 mil per every centimeter of a depth of a tray; 
 wherein the multi-layer tubular strip is: 
 co-extruded to produce a multi-layer co-extruded tubular strip; 
 the multi-layer co-extruded tubular strip is cooled by immersing the strip in water until the multi-layer co-extruded strip reaches a temperature between 10 to 50° C. to obtain an amorphous multi-layer tubular strip; 
 the amorphous multi-layer tubular strip is heated at a temperature of between 70 to 90° C. producing a heated strip; 
 the heated strip is expanded in two directions to obtain a dimension that covers a perimeter of the tray; and 
 the expanded strip is thermo-shrinked from 30 to 50% of the expanded strip until reaching the dimension of the tray. 
 
     
     
       2. The low thickness film in accordance with  claim 1  wherein the polyamide is selected from the group consisting of a Nylon 6 homopolymer, a Nylon 6/66 copolymer, and a Nylon 6/12 copolymer. 
     
     
       3. The low thickness film in accordance with  claim 1  wherein the ethyl vinyl alcohol includes a copolymer with at least 35% mol of ethyl vinyl alcohol. 
     
     
       4. The low thickness film in accordance with  claim 1 , wherein the sealing agent is selected from the group consisting of a vinyl acetate polymer with a modified anhydrous ethylene or a modified polyolefin with a functional group that promotes adherence to plastic materials. 
     
     
       5. The low thickness film in accordance with  claim 1  wherein the polyolefin is selected group consisting of a low density polyethylene (LDPE), a linear low density polyethylene (LLDPE), and metallocene. 
     
     
       6. The low thickness film in accordance with  claim 1 , wherein the film has a thermo-shrinking degree of from 5 to 30% when immersed in a water bath at 80° C. for at least 1 second.